eBay auctions Lady Gaga nude signed sketch by crooner Tony Bennett

It seems that Lady Gaga just can't get enough of the collectibles markets at the moment. The latest news is that a nude sketch of the eccentric pop star drawn by legendary crooner, Tony Bennett, is auctioning on eBay Celebrity, an offshoot of the popular auction website.

The sketch was drawn during a recent photoshoot to promote the singers' version of "The Lady Is a Tramp" for Bennett's recent Duets II album. Photographer Annie Leibovitz urged Lady Gaga to remove her clothes during the photoshoot and for Bennett, who is also a painter, to sketch her.

Born this way: Lady Gaga sketched by Tony Bennett - bids are open at $5,000

Bids for the rare sketch close in six days (at the time of writing) and have opened at $5,000. Proceeds will benefit Gaga and Bennett's respective Born This Way and Exploring the Arts foundations.

Highlights in the auction included a Gaga stage-worn outfit which brought $31,250. How this nude sketch compares in value - also bearing mind it has links to much-admired singer Bennett - remains to be seen.

Other popular lots at Julien's included a prop gun used in Gaga's recent video for her hit single "Born This Way". It sold for $7,680.

At the time, we commented that Lady Gaga signatures are particularly rare and sell for higher amounts than her pop contemporaries.

But whether Gaga is likely to leave a legacy for future generations - integral to her collectibles' future value - is open to debate.

One thing's for sure: the impact of Gaga memorabilia is certainly being felt on the current collectibles markets. If you're a fan, you may want to take a look at eBay Celebrity's sale before bids for her collectibles potentially soar.